Concept explainers
BIO Ultrasound Imaging. Sound having frequencies above the range of human hearing (about 20,000 Hz) is called ultrasound. Waves above this frequency can be used to penetrate the body and to produce images by reflecting from surfaces. In a typical ultrasound scan, the waves travel through body tissue with a speed of 1500 m/s. For a good, detailed image, the wavelength should be no more than 1.0 mm. What frequency sound is required for a good scan?
Learn your wayIncludes step-by-step video
Chapter 15 Solutions
University Physics with Modern Physics Plus Mastering Physics with eText -- Access Card Package (14th Edition)
Additional Science Textbook Solutions
College Physics
Essential University Physics: Volume 2 (3rd Edition)
University Physics Volume 1
Tutorials in Introductory Physics
Introduction to Electrodynamics
Essential University Physics (3rd Edition)
- A sound wave can be characterized as (a) a transverse wave, (b) a longitudinal wave, (c) a transverse wave or a longitudinal wave, depending on the nature of its source, (d) one that carries no energy, or (e) a wave that does not require a medium to be transmitted from one place to the other.arrow_forwardA sound wave traveling in air has a pressure amplitude of 0.5 Pa. What is the intensity of the wave?arrow_forwardFemale Aedes aegypti mosquitoes emit a buzz at about 4.00102 Hz, whereas male A. aegypti mosquitoes typically emit a buzz at about 6.00102 Hz. As a female mosquito is approaching a stationary male mosquito, is it possible that he mistakes the female for a male because of the Doppler shift of the sound she emits? How fast would the female have to be traveling relative to the male for him to make this mistake? Assume the speed of sound in the air is 343 m/s.arrow_forward
- During a thunderstorm, a frightened child is soothed by learning to estimate the distance to a lightning strike by counting the time between seeing the lightning and hearing the thunder (Fig. P2.25). The speed vs of sound in air depends on the air temperature, but assume the value is 343 m/s. The speed of light c is 3.00 108 m/s. a. A child sees the lightning and then counts to eight slowly before hearing the thunder. Assume the light travel time is negligible. Estimate the distance to the lightning strike. b. Using your estimate in part (a), find the light travel time. Is it fair to neglect the light travel time? c. Think about how time was measured in this problem. Is it fair to neglect the difference between the speed of sound in cold air (vs at 0C = 331.4 m/s) and the speed of sound in very warm air (vs at 40C = 355.4 m/s)?arrow_forwardSome studies suggest that the upper frequency limit of hearing is determined by the diameter of the eardrum. The wavelength of the sound wave and the diameter of the eardrum are approximately equal at this upper limit. If the relationship holds exactly, what is the diameter of the eardrum of a person capable of hearing 20 000 Hz? (Assume a body temperature of 37.0C.)arrow_forwardAt t = 0, a transverse pulse in a wire is described by the function y=6.00x2+3.00 where xand y are in meters. If the pulse is traveling in the positive x direction with a speed of 4.50 m/s, write the function y(x, t) that describes this pulse.arrow_forward
- Consider a diagnostic ultrasound of frequency 5.00 MHz that is used to examine an irregularity in soft tissue. (a) What is the wavelength in air of such a sound wave if the speed of sound is 343 m/s? (b) If the speed of sound in tissue is 1800 m/s, what is the wavelength of this wave in tissue?arrow_forwardSound is detected when a sound wave causes the eardrum to vibrate. Typically, the diameter of the eardrum is about 8.0mm in humans. When someone yells to you in a noisy environment, the sound intensity at your ear sometimes approximates 2 x 10-6 W/m2. Suppose that the 2 x 10-6 W/m2 of sound you are hearing comes from a janitor cleaning a rug by pulling a vacuum cleaner (at the end of a 1-meter-long tube oriented perpendicularly to the line separating you from the janitor). This person is yelling just over the din of the appliance in order to be heard by you. Estimate the distance between you and the janitorarrow_forwardUltrasound equipment used in the medical profession uses sound waves of a frequency above the range of human hearing. If the frequency of the sound produced by the ultrasound machine is f = 30 kHz, what is the wavelength of the ultrasound in bone, if the speed of sound in bone is v = 3000 m/s?arrow_forward
- A loud vacuum cleaner outputs 1.5 mW of sound energy. What is the intensity of the sound wave 2.0 meters away? (Give your answer in ?μW/m2.)arrow_forwardA hearing aid is essentially a system consisting of a tiny microphone, amplifier, and speaker. A particular hearing aid boosts the sound level by 36.0 dB. If a sound has a frequency of 500 Hz at an intensity of 2.90 x 10-11 W/m², what is the intensity (in W/m2) produced by the hearing aid? 1154.5 X Apply the definition of the sound level for the original and amplified sound, and write an equation for the difference. Solve for the amplified intensity. W/m²arrow_forwardYou're using an ultrasonic sensor in the deep depths of the ocean to identify shipwrecks. However, you first need to calibrate your sensor for these conditions, as the speed of sound is unknown in the cold, high pressure conditions you are working in. You set up an experiment in a lab where you recreate the environmental conditions of the deep ocean and place an object 30 m from an ultrasonic sensor. The total travel time of the ultrasonic wave is 33 ms (milliseconds). What is the speed of sound in these conditions?arrow_forward
- University Physics Volume 1PhysicsISBN:9781938168277Author:William Moebs, Samuel J. Ling, Jeff SannyPublisher:OpenStax - Rice UniversityPhysics for Scientists and Engineers: Foundations...PhysicsISBN:9781133939146Author:Katz, Debora M.Publisher:Cengage LearningPrinciples of Physics: A Calculus-Based TextPhysicsISBN:9781133104261Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning
- Physics for Scientists and Engineers, Technology ...PhysicsISBN:9781305116399Author:Raymond A. Serway, John W. JewettPublisher:Cengage Learning